The present invention relates to an indexing or stepping device or control for machines, comprising a circular plate provided with teeth and an arm longitudinally reciprocable parallel to the plane of the plate for rotating the plate through a predetermined angle.
Such a device, called indexing mechanism, is disclosed in U.S. Pat. No. 3,186,246. That device comprises a toothed plate and an arm longitudinally reciprocable parallel to the plane of the plate, to effect advancing rotary movements of the plate by forward and return movements of the arm. Driving and locking of the toothed plate in the prior device requires two pivoting pins mounted on springs, which makes the device complicated and delicate. Furthermore, it is impossible to interchange the toothed plate with other plates, whose teeth have a different pitch; the device is thus not a "universal" control or stepping device.
It is an object of the present invention to provide a universal control or stepping device. It is another object to provide such a device, using a toothed plate and a reciprocable arm, without special locking means, and to arrange it so that a movement of the arm in either direction ensures an advancing movement of the plate.
By way of example, the stepping device can be used, as is well known, to ensure exact angular positioning of a workpiece to be machined, or of a tool to be machined or ground, on which it is desired to carry out a succession of generally identical operations.